Replace Makara with an initial Rails 6 role based splitting method.

app/models/user.rb

@@ -155,26 +155,34 @@ class User < ApplicationRecord
   end
 
   def update_tracked_fields!(request)
-    super
-    prepare_returning_user!
+    ru = nil
+    ActiveRecord::Base.connected_to(role: :writing) do
+      super
+      ru = prepare_returning_user!
+    end
+    ru
   end
 
   def update_sign_in!(request, new_sign_in: false)
-    old_current, new_current = current_sign_in_at, Time.now.utc
-    self.last_sign_in_at     = old_current || new_current
-    self.current_sign_in_at  = new_current
+    ru = nil
+    ActiveRecord::Base.connected_to(role: :writing) do
+      old_current, new_current = current_sign_in_at, Time.now.utc
+      self.last_sign_in_at     = old_current || new_current
+      self.current_sign_in_at  = new_current
 
-    old_current, new_current = current_sign_in_ip, request.remote_ip
-    self.last_sign_in_ip     = old_current || new_current
-    self.current_sign_in_ip  = new_current
+      old_current, new_current = current_sign_in_ip, request.remote_ip
+      self.last_sign_in_ip     = old_current || new_current
+      self.current_sign_in_ip  = new_current
 
-    if new_sign_in
-      self.sign_in_count ||= 0
-      self.sign_in_count  += 1
+      if new_sign_in
+        self.sign_in_count ||= 0
+        self.sign_in_count  += 1
+      end
+
+      save(validate: false) unless new_record?
+      ru = prepare_returning_user!
     end
-
-    save(validate: false) unless new_record?
-    prepare_returning_user!
+    ru
   end
 
   def disable_two_factor!
@@ -233,6 +241,7 @@ class User < ApplicationRecord
   end
 
   def web_push_subscription(session)
+    return nil if session.nil?
     session.web_push_subscription.nil? ? nil : session.web_push_subscription
   end